Gas sensors, such as hydrogen sensors, are utilized in a number of commercial, consumer and industrial applications. Hydrogen, for example, is a flammable and explosive gas with a wide variety of industrial and scientific uses. Well-known industrial uses of hydrogen include the production of basic staple products of chemical industry such as ammonia and fertilizers derived therefrom, basic alcohols, hydrogen chloride, reduction of ores for manufacturing of metals, refinery of oil for manufacturing of petroleum, hydrogenation of vegetable oils for margarine and related industries, and many other uses.
Hydrogen is also widely used for space flight applications, for instance as a component of hydrogen-oxygen blends used in vehicular propulsion systems. Hydrogen is also used in a variety of metal forming and microelectronic processing steps which are often of extreme importance in device fabrication and metal interconnect processing of multi-level devices.
There has been also an increasing emphasis on the use of fuel cells, which require hydrogen as a fuel in various stationary and mobile applications, for instance, in fuel cells of automobiles.
It is axiomatic that handling hydrogen requires utilization of robust safety devices as it is a highly flammable gas at a concentration in air as low as 4% by volume. The ability to detect stray emissions of hydrogen is, therefore, mandatory, and is an important feature of any process or device where hydrogen is used.
In these and other applications, hydrogen sensors are employed to monitor the environment around which hydrogen is utilized, to ensure the efficiency, safety and operational integrity of the system. For such purposes, a number of hydrogen sensors and complex detection methods have been developed and are in common use.
Calibration and self-testing of sensors, such as hydrogen sensing devices, is an important feature for both safety and efficiency purposes. One of the problems with conventional sensor calibration and/or self testing methods and systems is that in order to successfully operate such devices, various chemical compounds must be heated quickly, efficiently and safely.